Conclusion: CWI between HIIT slowed V̇O2 on-kinetics, leading to increased anaerobic contribution during HIIT2. This detrimental effect of CWI was likely related to peripheral adjustments, because the slowing of V̇O2 on-kinetics was twofold greater than that of central delivery of O2 (i.e.,Q̇ ). CWI has detrimental effects on high-intensity aerobic exercise performance that persist for ≥45 min.